Disorders of the eyes are some of the most common concerns we see at Westgate Pet Clinic. Many are simple problems that require simple therapies to remedy. Others can be very serious, requiring aggressive, prompt treatment to prevent permanent damage. Occasionally disorders of the eyes are a sign of a systemic disease that requires treatment of underlying disease in order to help the eyes return to normal. Following are some common problems seen in pet dogs and cats.
Depending on where the redness is, these can be simple or complex problems. Redness of the eyelids could be a sign of allergies or infection of the glands of the eyelid (stye). Conjunctivitis, or inflammation of the lining of the eyelids, is one of the most common disorders we see. These can be primary, resulting from something as simple as dust or debris in the eyes or can be secondary to allergies or pain or inflammation of the cornea (surface of the eye) or sclera (white of the eye). Often conjunctivitis is accompanied by green or yellow discharge which may suggest infection.
Decreased tear production in the eyes, also called “dry eye” or keratoconjunctivitis sicca, causes thick mucus to be produced in order to keep the eye moist. A simple test called a schirmer tear test, can determine if your pet has normal tear production.
Glaucoma is caused by too much pressure in the eyeball (globe) itself. Glaucoma can cause inflammation of the conjunctiva and sclera and can make the eye look bigger than normal. It can also make the surface of the eye appear cloudy. Some breeds of dogs such as Bassett Hounds and Cocker Spaniels have a genetic predisposition to glaucoma but glaucoma can also be caused by trauma in any dog or cat. Glaucoma is an emergency situation, requiring prompt medical attention in order to prevent permanent blindness.
Corneal ulcers are also a common disorder in dogs and cats. They are most often caused by trauma, such as a stick or a scratch. Ulcers are most commonly diagnosed by putting a drop of fluorescein stain in the eye. Fluorescein is taken up by the inner layers of the cornea but not a normal corneal surface making an ulcer show up distinctly when a cobalt filtered light is shone on it.
Many people with older dogs comment on how the dog’s eyes look grey or cloudy. This is most often a result of nuclear sclerosis, a process where the outer layer of the lens thickens over time, allowing less light to reach the retina and thus reflecting some light back through the pupil causing the grey appearance. This is a benign change that is not painful or threatening to the dog, although it can make vision worse in dim lighting. Cataracts have a similar appearance but can actually cause blindness. Your veterinarian can easily distinguish between the two and can recommend any necessary treatment.
Occasionally we will see animals with disorders of the cornea (eye surface) itself, which can also cause a cloudy appearance to the eye(s). Some of these are benign and some can compromise the health of the eye and may require short or long term treatment.
Systemic Disease affecting the eyes:
There are many infectious diseases that can cause inflammation in the eyes or can even cause blindness. High blood pressure is a common cause of blindness in the cat by causing detachment of the retina. Advanced liver disease can make the sclera (white) of the eye turn a yellow color.
In summary, not all abnormalities of the eyes require treatment or bother the pet at all. However, because it can be difficult to differentiate between benign and serious problems of the eyes, it is best to have your pet examined by your primary veterinarian.